Apparatus for heating and sterilizing fluids.



No. 638,!92. Patented Nov. 28, 189 9. A. a. WATERHDUSE & J. s. ronses. APPARATUS FOR HEATING AND STERILIZING FLUIDS.

(Application filed Nov. 14, 1898.) (No Model.)

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ADDISON c. WATERHOUSE AND JOHN s. FORBES, on PHILADELPHIA, .PENi i SYLVANIA, ASSIGNORS TO WATERHOUSE-FORBES 00., or SAME PLACE.

APPARATUS FOR HEATING AND STERILIZING FLUIDS;

SPECIFICATION forming part of Letters Patent No. 638,192, dated November 28, 1899.

Application filed November 14, 1898. Serial No. 696,482. (No model.)

To ctZZ whom it may concern.- ment under which the fluid passes for auto- Be it known that we, ADDISON G. WATER- matically regulating the flow of such fluid to HOUSE and JOHN S. FORBES, citizens of the accord with any predetermined temperature United States, residing at the city of Philaat which it is to be treated.

5 delphia, in the State of Pennsylvania, have To avoid the objection to the above-named invented a new and useful Apparatus for methods, we have made this present inven- Heating and sterilizing Fluids, of which the tion, which embraces means for employing following is a specification. indirectly the expansive effect of any degree Our invention relates to the art of heating of heat without causing ebullition, which may 10 water, milk, and other fluids for the purpose be applied to the fluid under treatment for of destroying disease-germs; also, for producautomatically causing and controlling the ing chemical effects and other useful purflow of such fluid through the apparatus. The

poses in the arts. same results can be accomplished by employ- We are aware that attempts have been ing directly the expansive effect of heat on I 5 made to form automatic sterilizers whereby the fluid under treatment by means which we milk and other fluids could be heated to a prereserve for a subsequent application.

determined temperature; but in these cases Our present invention further consists of the flow of the fluid was regulated by valves means for conserving the heat applied by or other mechanical contrivances which postransferring the heat imparted to the fluid on 2o sessed the inherent defects peculiar to meits way from where heat is applied to the cold chanical contrivance or the positive objection fluid to be treated while on its way to where to valves on the score of leakage, corrosion, heat is applied, and also of certain details and unreliability, and also automatic heaters and parts belonging to and adapted for the and sterilizers have been made and used carrying out of our invention. 25 wherein the fluid to be treated is drawn from Therefore the leading object of our invena source of supply below the level required tion is to form an apparatus which shall posfor causing it to flow through the apparatus, sess the inherent elements necessary for auand wherein means are employed for causing tomatically performing the following functhe fluid to pass through the apparatus as it tionsz first, heating all the fluid being treated 30 is raised above its normal level while in a to any predetermined temperature; second,

state of ebullition caused by raising the fluid preventing any of the fluid being treated to the boiling-point by the application of heat. from passing through the apparatus by leaks There are two objections to the last-aboveor otherwise until it has been raised to the mentionedmethods. The first objection rests desired temperature, and, third, preventing 5 upon its limited range of utility for the treatthe fluid being treated from being overheated.

- ment required for different fluids, and vari- In order to fully set forth our invention, refous purposes call for a wide range of temerence willbe had to the accompanying drawperature above and below the boiling-point. ings made a part hereof, in which- Therefore the state of ebullition which is in- Figure 1 shows diagrammatically an appa- 0 4o cidental to the boiling-point is not available ratus embodying the different parts of our as a means of regulation in cases where the invention. Fig. 2- is a sectional plan of a boiling-point does not correspond with the heat-exchange. Fig. 3isasectional elevation temperature required for treating different of part of Fig. 2. Fig. 4 is a sectional view fluids or for effecting Various resultsas, for of a modified form of heat-exchange. 5 45 instance, in sterilizing milk, which must be Fig. 1 shows diagrammatically a supplytreated at a temperature below its boilingpipe at and a closed receiving-tank at, having point in order to avoid cooking the same and a valve a actuated by a float a C is a pipe impairing its quality. In such fluid, therewhich extends downward from a to a heatfore, it is necessary to avoid boiling the same exchange E, consisting of two separate com- 50 or causing the state of ebullition and still empartments d and 1;, which are formed within ploy means which are incidental to the treatthe outer shell of E by means of the partition R. The pipe 0, which leads from tank a, enters at the lower extremity of compartment 61. Atthe upper extremity of d is an aperture d, leading into a closed heater H. Within H is a closed air or vapor chamber L, which is connected by a tube L to the tank a, so that there is an air communication leading from the chamber L to the part of the tank a above the water-level S. The tube L may be provided with an air-pump L as shown, for regulating the initial pressure in L. Leading from the top of the heater H is a pipe or passage h, which extends upward above the water level S to a level represented by T, where the pipe takes a downward turn and forms a weir or overflow aperture fand then extends down, as shown by pipe h, and enters the upper extremity of the compartment 2' of the heat-exchange E. From the lowerend of compartmentt' the pipe j extends, which termihates at the discharge K. H represents a gas-burner or means of applying heat to the heater I-I. y

In operation, the fluid to be treated enters at the supply-pipe a into the closed tank a and passes down through the pipe 0 until it fills the compartment cl and the heater H and rises in the pipe h to the water-level S. When the fluid reaches the level S in pipe h, it also rises to the same level in the closed tank a. a

This raises the float a and closes the valve a so that the fluid is restrained from rising above the level S, but is allowed to pass through the valve a when the fluid is below that level. So when the entering fluid is restrained or limited to the level S it is obvious that it cannot flow over the weir fin pipe h and pass through the apparatus, because the weir f is above the level S or at the higher level T. Therefore the fluid will stop flowing after it rises to the level S in tank a and pipe h and come to a standstill. If heat is applied to the heater H until the temperature of the fluid is raised to a higher temperature than it had when entering a, the heated fluid in H, which surrounds the closed air vessel L, will expand the air in L and cause it to flow through the tube L and exert a pressure upon the fluid in tank a, and this air-pressure in pressing down upon the surface of the fluid in a will cause the fluid to rise in pipe h to a level above that of S, and the level to which it will rise depends upon the amount the air in L is expanded, which in turn depends upon the degree of temperature to which the fluid in H, and consequently the air in L, is raised. The weir f can be adjusted to a proper height above the level S to correspond to ,the temperature at which it is desired to treat the fluid. It is obvious under these conditions that as a certain degree of heat will raise the fluid in pipe h to the level necessary to overflow the weir f any less heat than that required will fail to raise it to the overflowlevel, so that it will not pass through the apparatus. While, on the other hand, any excess of heat will raise it above the weir f fluid. Therefore the apparatus is capable of preventing any fluid from passing through it until it is raised to the required temperature and causing it to flow at a rate which will be beyond the capacity of the applied heat to overheat the same. After the heated fluid passes over the weirfit flows down through pipe h and fllls the compartment 2' of the heat exchange E, and while this fluid is passing down through the compartment 2' its heat is being conducted through the partition R to the cold fluid passing up through the compartment d, so that by the time the heated fluid reaches the lower extremity of compartment 7; and is ready to pass off through pipe j and discharge K it is cooled down to nearly its original temperature, while the cold fluid which enters the lower extremity of compartment d absorbs this heat, and by the time it reaches the heater H it is raised to nearly the desired temperature. Therefore but a small amount of heat is required to operate the apparatus, as the same heat is conserved and used over and over again.

In the construction of this apparatus several important details are involved, one leading feature being the heat-exchange (represented by E in the drawings.) The main object to attain in constructing these exchanges is to produce the greatest practical surface in the partition B, so as to facilitate the transfer of heat from the fluid in one compartment to that in the other; also, to form this partition so that if any leak occurs owing to imperfect joints these leaks will occur from the compartments outward through the joints of the external shell and not from one compartment to the other; also, to have the external shell compact, so as to possess the least possible surface through which heat can be lost into the surrounding air, and in case of small apparatus or where they are made in short or compact form to have the compartments formed so that the movement of the fluid through them will meet with the least possible resistance in order that agitation may be avoided and the fluid be allowed to stratify, so that each part will take a level according to its temperature, ranging so that the hottest will be on top and the coldest at the bottom,

or so that the hot fluid in one compartment will sink as it gradually gives up its heat until it passes out through the bottom cold, while the cold fluid in the other compartment will rise as it gradually absorbs heat until it passes out at the top hot. With these objects in view we have constructed a heat-exchange, as represented by Fig. 2, which shows a sectional end or top view. Its outer shell is composed of two light shells E and E placed together as shown, with the intervening partition B so thatit will extend from the joint E across the interior space formed by these esaie s shells until it reaches the joint E The form of this partition R is that of a many-counterfolded sheet, so that it crosses from E to E in a back-and-forth direction and offers a 5 large surface compared to that of E and E These three parts are all held together by flanges or riveted joints E and E and then dipped in melted metal, such as zinc or tin,

so that the joints are closed and the surface IQ of the metal is coated. This partition R divides the inner space into two compartments d and 'i. If there is any leak from the joints E or E from either compartment, it will be outward through the outer shell or through these joints and not from one compartment to the other. The fluids enter at the extremes of the compartments d and t and have a straight passage in a direction parallel to the partition B. Fig. 3 is a sectional elevation showing the folded partition B. One of the ends of this exchange is closed by means of cement or metal cast or molded while in a liquid state in the form shown by P, which stops off all the openings at the end of parti- 2 5 tion R and also completely closes each end of the two compartments formed on each side of this partition.

Fig. 4 shows a heat-exchange, in which E represents a case inclosing two sides and the top and bottom of the partition R. The ends (not shown) are closed by metal cast in, as described in Fig. 3. In this form the two compartments are made accessible by removing the front and back plates E and E What we claim as our invention is- 1. In a fluid-heater as described, the combination of a closed supply-tank provided with means for maintaining a constant level to the fluid supplied thereto, a closed expansion-chamber having a passage leading from the same to the surface of the fluid in the supply-tank, and means for conducting heat from the'fluid being treated, to the air or liquid in the expansion-chamber, whereby the pressure caused by the expansive effect of heat within the expansion-chamber, will force the heated fluid within the apparatus, to a level above its normal point, and cause the same to pass through the apparatus; substantially as described.

2. In a fluid-heater as described, the combination of a closed supply-tank with means for maintaining the fluid-level therein constant, a heat-exchange through which the fluid passes on its Way to and from the point where heat is applied, a closed expansionchamber containing air or liquid with means for conducting heat from the heated fluid to the air or liquid within the expansion-chamher, and means for employing the expansive force of the heat conducted to the air or fluid within the expansion-chamberfor causing the heated fluid to rise and flow over a weir above its normal level substantially as described.

3. A heat-exchange composed of two elongated parallel' compartments divided by a folded back-and-forth partition and inclosed around its side by shells provided with inlet and outlet apertures at the extremes of each compartment, and being closed at the ends by cast material adapted for forming an im pervious separation between the two compartments; substantially as and for the purposes set forth.

4. A heat-exchange composed of two halfshells E and E the folded partition R extending out through the joints E and E and the cast sealing material P at the end; substantially as and for the purposes set forth. 8o

ADDISON G. WATERHOUSE. JOHN S. FORBES.

Witnesses:

C. O. BEAUMONT, H. L. DAVIS. 

